There have been many different types and kinds of security systems and methods for using them relating to the controlling of access to a secured or protected area.
Conventional security systems of the general type with which the present invention is concerned are employed for controlling access to security or protected areas in which only authorized personnel are permitted to enter. The conventional, prior known, entry security systems include a single door security system, as well as a double door security system. With respect to the double door system, an authorized person unlocks a secured door and enters a vestibule or semi-secure area, and then closes and locks the secured door. The authorized person unlocks a second door and proceeds into the protected or secured area.
While the double door security system may have been successful in some applications, it has proved to be less than satisfactory in that a determined intruder with a gun or other life threatening weapon could lay in wait and compel the authorized person to unlock the secured door, enter the semi-secure area with the authorized person and then further compel the authorized person to unlock the second door to obtain access to the protected or secured area. Thus, the only determining factor in preventing the intruder from entering the secured area, is the willingness of the authorized person to risk bodily harm or death in refusing to unlock the doors to gain entry into the protected or secured area. Moreover, because the intruder can force the authorized person into the secured area, there is a present danger that the intruder will harm the authorized person in the secured area, once access has been achieved.
In an attempt to overcome the above-mentioned problems, the single door system with a small vestibule area has been employed.
With respect to the single door type systems, an authorized person can unlock a door which may then be swung open to a fixed point position to close off an entranceway to a secured area or room. Once the door reaches the fixed point position, it is automatically locked, and the authorized person is permitted to enter into a small, confined vestibule area formed by the ceiling, floor, walls and the door. By design, this area is only large enough to allow one person to fit comfortably therewithin. Once the authorized person has entered the area, he or she may unlock the door from its fixed position and thus, allowing the door to close to its original position When the door reaches its original position, it once again locks. The authorized person may then walk out of the vestibule area through the entranceway, which was previously blocked by the door in its fixed point position, and into the secured or protected area.
While the single door security system may have been successful for some applications, it too has not proved to be entirely satisfactory for all applications. Due to construction considerations, the size of the vestibule area should be sufficiently large to permit a large person to enter through it. Accordingly, if an authorized person has a small or medium size build, then a determined intruder with a small build can fit into the small vestibule area along with the authorized person and thus gain access into the secured or protected area, under threat of bodily harm with the authorized person.
Therefore, it would be highly desirable to have a security system which would prevent, or at least greatly reduce, the possibility of an unauthorized person following the authorized person, into the secured or protected area.